ETC Flashcards
Heme A
Long isoprenoid tail
Detected at 600nm
Heme B where can it be found
Myoglobins
Haemoglobins
B type cytochrome
What does heme B contain
Iron protoporphyrin IX
Not an isoprenoid tail
Heme C
Cytochrome C via thioester bonds to two cysteine residues
What do all haems contain
4/5 nitrogen ring in a cyclic structure
What does the 4/5 nitrogen ring form
Porphyrin
What are the 3 types of Fe-s centres in heme
Simple
Intermediate
Complex
What does the simple Fe-s contain
Iron + sulphur with cysteine residues
What does intermediate Fe-s contain
2 iron
2 sulphur
Connected via inorganic sulphur on cysteine
What does complex Fe-s contain
4iron
4 sulphur
Inorganic sulphur binds
Complex 1 structure
2 membrane arm
What does complex 1 catalyse the reaction of
Vectorial reaction
2 electrons donated by NADH pass into what in complex 1
FMN
How many Fe-s centres do the 2 electrons go through complex 1
Where do they go to
6-8 Fe centres
N-2 centre
2 protons get pumped into the matrix arm to form with what in complex 1?
Ubiquinone (Q)
Ubiquinone forms with what to form what in complex 1
Ubiquinone forms with 2 electrons/protons
Forms ubiquinol (QH2)
What’s fully reduced in complex 1
What’s fully oxidised in complex 1
QH2 = fully reduces
Q = fully oxidised
How many protons are pumped in complex 1
4
Complex 2 contains ABCD subunits, which are integrated into the membrane
C and D
Succinate can donate how many electrons in complex 2
Where does succinate come from
2 electrons
From citric Acid
Succinate after donating 2 electrons becomes what
What accepts these electrons
Fumerate
FAD reduced —> FADH2
What does the 2 electrons in complex 2 pass through?
3x Fe-s centres
Heme B (with iron protoporphyrin IX)
What’s formed in complex 2
QH2
Electrons can be donated to complex 2 from citric acid cycle (succinate) as well as? (2)
Fatty acid CoA
Glycerol 3 phosphate
In complex 3, one electron passes through what to cytochrome C (2)
What does this drive the process of
Rieske centre (2Fe-s)
Heme C1
Pumps 2 protons our
What does the other electron go towards in complex 3 instead of rieske centre
What does this process pump
Forms with Ubiquinone (Q) to form Semi radical (Q-)
2 protons into complex
2 protons pumped into the complex 3 form with what to form QH2
What does this then allow
Form with semi radical Q-
Allows reaction to start again
Allowing 4 protons to be pumped out
How many subunits are present at complex IV
13 subunits
3 main subunits
What does unit 1 contain on complex IV
CUb
Heme A
Heme A3
Unit 2 contains what on complex IV
Cu A
What donates electrons to complex IV
What do these form
2x Reduced Cytochrome C
2 oxidised cytochrome C
What does the 2 electrons donated pass through on complex IV
Unit 2 (CUA)
Unit 1 (A / A3 /CUB)
What do the 2 electrons in complex IV form with
1/2 O2 + 2 protons
Forms H20
How many protons are pumped out of complex IV
2 protons
What drug inhibits complex 1 and prevents QH2 formation
Rotenone
Complex 3 is inhibited by what
Antimycin
What inhibits complex IV
Cyanide
What happens to the pH of the matrix has protons are pumped into the intermembrane space
Becomes alkali
What does the F0 region contain
A
B2
C10
What does the F1 region contain
a3
B3
D (Greek)
E(Greek)
What is the central stalk of the F1 to F0
Y
What does the B2 unit of F0 attach to on F1
Delta
What’s the role of ATP synthase
Convert proton gradient energy into chemical energy
What are the 3 confirmations of Beta3
B-ATP conformation
B-Empty
B-ADP
ATP forms through what type of reaction
Condensation
How many ATP/360
3ATP
Overall how many ATP are produced using P/O ratio of (2.5/1.5)
30-32
How many protons are used in synthesis of ATP
1 = transport ATP/ADP/PI
3 = needed to synthesise ATP
What does imcreased respiration do on ATP production
More ATP production
As more 1/2 O2 reduced into water
How many protons pumped from succinate
6
How many protons pumped per NADH
10
What can produce antimycin A
Streptomyces bacteria
